What is the Fourth Metacarpal Bone
This bone is associated with the ring finger, contributing to the structure of the palm and enabling proper hand function [1]. It consists of a head and a base, connected by the elongated shaft [2].
Where is it Located
As the fourth of the metacarpals, it is positioned between the distal carpal bones and the fourth proximal phalanx [3].
Fourth Metacarpal
Development and Ossification
Ossification of this bone begins with two separate centers, one for the head and another for the shaft [4]. The shaft’s ossification starts during the early stages of fetal development, while the head begins to ossify around the third week of life [5].
Fourth Metacarpal X-Ray Image
Anatomy of the Ring Finger Metacarpal: Surfaces and Joints
At its base, there are two proximal facets articulating with the distal carpal bones capitate and hamate. There are also two more articular surfaces at the base, medially and laterally, joining the fourth metacarpal with the third and fifth metacarpals respectively. On the distal end, it has an articular facet on its head for the fourth proximal phalanx base [6].
Common Injuries and Associated Conditions
Fractures of the metacarpal bones are among the most prevalent bone injuries [3], and a fracture in the fourth and fifth metacarpals is often termed a boxer’s fracture, as it frequently occurs from forcefully punching with a closed fist [8]. Overuse injuries and arthritis of the joints of this metacarpal may also develop, but they are less common than those affecting the carpometacarpal joint of the thumb.
Shortening of the fourth metacarpal is a condition that impedes the growth of the bone or causes it to shorten. It may result from an injury, post-operative trauma, or an underlying bone abnormality – the precise causes are still not fully known. In many cases, there is no change in the hand’s function, aside from the finger looking shorter [7].
References
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- http://teachmeanatomy.info/upper-limb/bones/bones-of-the-hand-carpals-metacarpals-and-phalanges/
- https://www.earthslab.com/anatomy/carpometacarpal-joints/
- https://www.healthline.com/human-body-maps/metacarpals
- https://www.bartleby.com/107/56.html
- https://prohealthsys.com/central/anatomy/grays-anatomy/index-10/index-10-2/index-10-2/ossificationhand/
- https://www.kenhub.com/en/library/anatomy/the-metacarpal-bones
- https://radiopaedia.org/articles/shortening-of-the-fourthfifth-metacarpals
- https://www.webmd.com/a-to-z-guides/boxers-fracture
